Mybatis Plus结合Redis实现自定义缓存

一、准备工作

1.Redis工具类

import org.springframework.data.redis.core.RedisCallback;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.util.CollectionUtils;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.TimeUnit;

/**
 * Redis工具类,一般企业开发常用的一个工具类，不会去用原生的redis配置类
 */

public final class RedisUtils {

    private RedisTemplate<String, Object> redisTemplate;

    public RedisUtils(RedisTemplate<String, Object> redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    public Object execute(RedisCallback action) {
        Object execute = redisTemplate.execute(action);
        return execute;
    }

    /**
     * 删除Collection集合中的key
     *
     * @param keys
     * @return
     */
    public Long del(Collection<String> keys) {
        Long delete = redisTemplate.delete(keys);
        return delete;
    }

    /**
     * 模糊查询key
     *
     * @param str 模糊查询的条件
     * @return
     */
    public Set<String> keys(String str) {
        Set<String> keys = redisTemplate.keys(str);
        return keys;
    }

    /**
     * 消息订阅与发布：发布
     *
     * @param channel
     * @param message
     */
    public void convertAndSend(String channel, Object message) {
        redisTemplate.convertAndSend(channel, message);
    }

    /**
     * 如果不存在且保存的时间大于0即可创建成功，否则创建失败
     *
     * @param key   键
     * @param value 值
     * @param time  缓存的时间
     * @return
     */
    public boolean setNx(String key, Object value, long time) {
        try {
            if (time > 0) {
                return redisTemplate.opsForValue().setIfAbsent(key, value, time, TimeUnit.SECONDS);
            } else {
                return false;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    /**
     * 如果不存在才创建成功，否则就创建失败
     *
     * @param key
     * @param value
     * @return
     */
    public boolean setNx(String key, Object value) {
        try {
            return redisTemplate.opsForValue().setIfAbsent(key, value);
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    // =============================common============================
    public boolean expire(String key, long time) {
        try {
            if (time > 0) {
                redisTemplate.expire(key, time, TimeUnit.SECONDS);
            }
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public long getExpire(String key) {
        return redisTemplate.getExpire(key, TimeUnit.SECONDS);
    }

    public boolean hasKey(String key) {
        try {
            return redisTemplate.hasKey(key);
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public void del(String... key) {
        if (key != null && key.length > 0) {
            if (key.length == 1) {
                redisTemplate.delete(key[0]);
            } else {
                redisTemplate.delete((Collection<String>) CollectionUtils.arrayToList(key));
            }
        }
    }

    // ============================String=============================
    public Object get(String key) {
        return key == null ? null : redisTemplate.opsForValue().get(key);
    }

    public boolean set(String key, Object value) {
        try {
            redisTemplate.opsForValue().set(key, value);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public boolean set(String key, Object value, long time) {
        try {
            if (time > 0) {
                redisTemplate.opsForValue().set(key, value, time, TimeUnit.SECONDS);
            } else {
                set(key, value);
            }
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public long incr(String key, long delta) {
        if (delta < 0) {
            throw new RuntimeException("递增因子必须大于0");
        }
        return redisTemplate.opsForValue().increment(key, delta);
    }

    public long decr(String key, long delta) {
        if (delta < 0) {
            throw new RuntimeException("递减因子必须大于0");
        }
        return redisTemplate.opsForValue().increment(key, -delta);
    }

    // ================================Map=================================
    public Object hget(String key, String item) {
        return redisTemplate.opsForHash().get(key, item);
    }

    public Map<Object, Object> hmget(String key) {
        return redisTemplate.opsForHash().entries(key);
    }

    public boolean hmset(String key, Map<String, Object> map) {
        try {
            redisTemplate.opsForHash().putAll(key, map);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public boolean hmset(String key, Map<String, Object> map, long time) {
        try {
            redisTemplate.opsForHash().putAll(key, map);
            if (time > 0) {
                expire(key, time);
            }
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public boolean hset(String key, String item, Object value) {
        try {
            redisTemplate.opsForHash().put(key, item, value);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public boolean hset(String key, String item, Object value, long time) {
        try {
            redisTemplate.opsForHash().put(key, item, value);
            if (time > 0) {
                expire(key, time);
            }
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public void hdel(String key, Object... item) {
        redisTemplate.opsForHash().delete(key, item);
    }

    public boolean hHasKey(String key, String item) {
        return redisTemplate.opsForHash().hasKey(key, item);
    }

    public double hincr(String key, String item, double by) {
        return redisTemplate.opsForHash().increment(key, item, by);
    }

    public double hdecr(String key, String item, double by) {
        return redisTemplate.opsForHash().increment(key, item, -by);
    }

    // ============================set=============================
    public Set<Object> sGet(String key) {
        try {
            return redisTemplate.opsForSet().members(key);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public boolean sHasKey(String key, Object value) {
        try {
            return redisTemplate.opsForSet().isMember(key, value);
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public long sSet(String key, Object... values) {
        try {
            return redisTemplate.opsForSet().add(key, values);
        } catch (Exception e) {
            e.printStackTrace();
            return 0;
        }
    }

    public long sSetAndTime(String key, long time, Object... values) {
        try {
            Long count = redisTemplate.opsForSet().add(key, values);
            if (time > 0) {
                expire(key, time);
            }
            return count;
        } catch (Exception e) {
            e.printStackTrace();
            return 0;
        }
    }

    public long sGetSetSize(String key) {
        try {
            return redisTemplate.opsForSet().size(key);
        } catch (Exception e) {
            e.printStackTrace();
            return 0;
        }
    }

    public long setRemove(String key, Object... values) {
        try {
            Long count = redisTemplate.opsForSet().remove(key, values);
            return count;
        } catch (Exception e) {
            e.printStackTrace();
            return 0;
        }
    }

    // ===============================list=================================
    public List<Object> lGet(String key, long start, long end) {
        try {
            return redisTemplate.opsForList().range(key, start, end);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public long lGetListSize(String key) {
        try {
            return redisTemplate.opsForList().size(key);
        } catch (Exception e) {
            e.printStackTrace();
            return 0;
        }
    }

    public Object lGetIndex(String key, long index) {
        try {
            return redisTemplate.opsForList().index(key, index);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public boolean lSet(String key, Object value) {
        try {
            redisTemplate.opsForList().rightPush(key, value);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public boolean lSet(String key, Object value, long time) {
        try {
            redisTemplate.opsForList().rightPush(key, value);
            if (time > 0) {
                expire(key, time);
            }
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public boolean lSet(String key, List<Object> value) {
        try {
            redisTemplate.opsForList().rightPushAll(key, value);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public boolean lSet(String key, List<Object> value, long time) {
        try {
            redisTemplate.opsForList().rightPushAll(key, value);
            if (time > 0) {
                expire(key, time);
            }
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public boolean lUpdateIndex(String key, long index, Object value) {
        try {
            redisTemplate.opsForList().set(key, index, value);
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public long lRemove(String key, long count, Object value) {
        try {
            Long remove = redisTemplate.opsForList().remove(key, count, value);
            return remove;
        } catch (Exception e) {
            e.printStackTrace();
            return 0;
        }
    }
}

2.Redis配置模版

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.jsontype.impl.LaissezFaireSubTypeValidator;
import com.newbniz.newbbs.utils.RedisUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

@Configuration
@Slf4j
public class RedisConfig {

    /**
     * redis配置模板
     **/
    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {

        //为了开发的方便，一般直接使用
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(factory);

        //json的序列化配置
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.activateDefaultTyping(
                LaissezFaireSubTypeValidator.instance,
                ObjectMapper.DefaultTyping.NON_FINAL,
                JsonTypeInfo.As.PROPERTY);
        jackson2JsonRedisSerializer.setObjectMapper(om);

        //String的序列化
        StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();

        // key采用String的序列化方式
        template.setKeySerializer(stringRedisSerializer);

        // hash的key也采用String的序列化方式
        template.setHashKeySerializer(stringRedisSerializer);

        // value序列化方式采用jackson
        template.setValueSerializer(jackson2JsonRedisSerializer);

        // hash的value序列化方式采用jackson
        template.setHashValueSerializer(jackson2JsonRedisSerializer);

        template.afterPropertiesSet();

        return template;
    }

    @Bean(name = "redisUtils")
    public RedisUtils redisUtils(final RedisTemplate<String, Object> redisTemplate) {
        final RedisUtils jedisService = new RedisUtils(redisTemplate);
        return jedisService;
    }

}

3.手动获取bean的工具类

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

/**
 * @ClassName : ApplicationContextUtil
 * @Description : 手动获取bean的工具类
 */
@Component
public class ApplicationContextUtil implements ApplicationContextAware {
    private static ApplicationContext context;

    /**
     * @param beanName
     * @return
     */
    public static Object getBean(String beanName) {
        return context.getBean(beanName);
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.context = applicationContext;
    }
}

二、Mybatis Plus结合Redis实现缓存

1.自定义缓存管理类

package com.newbniz.newbbs.utils;

import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.cache.Cache;
import org.springframework.data.redis.connection.RedisServerCommands;
import org.springframework.data.redis.core.RedisCallback;
import org.springframework.util.DigestUtils;

import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * @ClassName : MybatisRedisCache
 * @Description : mybatis-plus结合redis自定义缓存管理
 * @author ZJ
 */
@Slf4j
public class MybatisPlusRedisCache implements Cache {


    /**
     * 注意，这里无法通过@Autowired等注解的方式注入bean,只能手动获取
     */
    private RedisUtils redisUtil;

    /**
     * 手动获取bean
     *
     * @return
     */
    private void getRedisUtil() {
        redisUtil = (RedisUtils) ApplicationContextUtil.getBean("redisUtils");
    }


    // 读写锁
    private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock(true);


    private String id;

    public MybatisPlusRedisCache(final String id) {
        if (id == null) {
            throw new IllegalArgumentException("Cache instances require an ID");
        }
        log.info("二级缓存id：{}",id);
        this.id = id;
    }


    @Override
    public String getId() {
        return this.id;
    }

    @Override
    public void putObject(Object key, Object value) {
        log.info("存入缓存");

        if (redisUtil == null) {
            getRedisUtil();//获取bean
        }

        try {
            //将key加密后存入
            redisUtil.hset(this.id,this.MD5Encrypt(key),value);
        } catch (Exception e) {
            log.error("存入缓存失败！");
            e.printStackTrace();
        }


    }

    @Override
    public Object getObject(Object key) {
        log.info("获取缓存");

        if (redisUtil == null) {
            getRedisUtil();//获取bean
        }

        try {
            if (key != null) {
                return redisUtil.hget(this.id,this.MD5Encrypt(key));
            }
        } catch (Exception e) {
            log.error("获取缓存失败！");
            e.printStackTrace();
        }

        return null;
    }

    @Override
    public Object removeObject(Object key) {
        log.info("删除缓存");

        if (redisUtil == null) {
            getRedisUtil();//获取bean
        }


        try {
            if (key != null) {
                redisUtil.del(this.MD5Encrypt(key));
            }
        } catch (Exception e) {
            log.error("删除缓存失败！");
            e.printStackTrace();
        }

        return null;
    }

    @Override
    public void clear() {
        log.info("清空缓存");
        if (redisUtil == null) {
            getRedisUtil();//获取bean
        }

        try {
            redisUtil.del(this.id);
        } catch (Exception e) {
            log.error("清空缓存失败！");
            e.printStackTrace();
        }

    }

    @Override
    public int getSize() {
        if (redisUtil == null) {
            getRedisUtil();//获取bean
        }
        Long size = (Long)redisUtil.execute((RedisCallback<Long>) RedisServerCommands::dbSize);
        return size.intValue();
    }

    @Override
    public ReadWriteLock getReadWriteLock() {
        return this.readWriteLock;
    }

    /**
     * MD5加密存储key,以节约内存
     */
    private String MD5Encrypt(Object key){
        String s = DigestUtils.md5DigestAsHex(key.toString().getBytes());
        return s;
    }

}

2.Mapper类加注解

@Repository
//对需要缓存的加注解
//下面这个↓
@CacheNamespace(implementation= MybatisPlusRedisCache.class,eviction=MybatisPlusRedisCache.class)
public interface xxxxxMapper extends BaseMapper<ForumArticle> {

}

3.Mapper.xml文件开启二级缓存

DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.newbniz.newbbs.mapper.XxxxMapper">
	
	
    <cache-ref namespace="com.newbniz.newbbs.mapper.XxxxMapper"/>
mapper>